Ferguson landslide

Coordinates: 37°39′24″N 119°54′3″W / 37.65667°N 119.90083°W / 37.65667; -119.90083
Source: Wikipedia, the free encyclopedia.
Ferguson Slide

The Ferguson landslide, also commonly called the Ferguson Slide, is an active landslide in the Merced River canyon in Mariposa County, California, United States. In 2006, rocks and debris slid off Ferguson Ridge, blocking California State Route 140, a primary access road to Yosemite National Park.[1] The slide still blocked the original road as of late 2021, although temporary bridges allow one-way traffic around the slide and into the park. The slide is a natural phenomenon, and resulted from the erosion dynamics of the river valley.[2]

History

The slide began on April 29, 2006, and initially the highway remained open, with active monitoring and occasional temporary closures. By May 28, the road was closed permanently, stopping access to the park from

State of Emergency was declared in June 2006 for Mariposa County.[2]

The downstream temporary bridge

Initially, two temporary bridges were built in August 2006. While this detour alleviated a significant portion of the economic impact to the area, vehicles over 28 feet could not use it. In June 2008, new temporary bridges which could accommodate longer vehicles were constructed. The detour via the bridges is one-way, controlled by traffic lights. At the height of the tourist season, this has sometimes resulted in significant delays.[2] The temporary bridges access a road grade on the north side of the Merced River, which is a vestige of the Yosemite Valley Railroad.

Repair of the highway was on permanent hold due to the encroachment of an endangered species into the slide area. In 2012, Assemblymember Kristin Olsen authored legislation that would allow the California Department of Fish and Game to do an initial take of the

Caltrans settled on a rock shed design in 2014.[5]

Ferguson Rock Shed

Caltrans plans to restore the original route of Highway 140 by building a protective rock shed, with construction split into two distinct projects:[6]

  • Phase 1: Removing the existing talus material (approx. 147,000 tons) and installing cable drapery to minimize additional rock fall. Work began in early 2021.
  • Phase 2: Constructing a 675-foot (206 m) rock shed structure on the same alignment.

Construction on the rock shed is expected to begin in Fall 2022 and last five years.[6]

References

  1. ^ Bailey, Eric (January 8, 2007). "Nature reclaims Yosemite route". Los Angeles Times. Retrieved November 13, 2021.
  2. ^ a b c DOT 2014.
  3. ^ "Caltrans New Strategy for Ferguson Project in Mariposa County Could Result in Cost Savings". Sierra Sun Times. May 22, 2015. Retrieved November 13, 2021.
  4. ^ "Bill Text - AB-1973 Protected species: take: Ferguson Slide Permanent Restoration Project". Retrieved June 10, 2015.
  5. ^ Skindrud 2014.
  6. ^ a b "Ferguson Rock Shed Project". California Department of Transportation. Retrieved November 13, 2021.
Attributions

External links

37°39′24″N 119°54′3″W / 37.65667°N 119.90083°W / 37.65667; -119.90083